JP3553450B2 - Rolling mill - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a running pair cross type rolling mill in which upper and lower work rolls and a backup roll are crossed during rolling of a sheet material to control the shape of the sheet, and a method of reducing the running force during the running.
[0002]
[Prior art]
2. Description of the Related Art In recent years, in a pair-cross type rolling mill in which upper and lower work rolls and a backup roll are simultaneously and integrally crossed to control a plate shape, a so-called running cross, which crosses during rolling of a sheet material, is essential.
[0003]
At this time, conventionally, as shown in FIG. 6, the top (upward from the pass line) of the housing 104 in which the upper and lower work rolls 100 and the backup roll 101 are rotatably supported via chocks 102 and 103, respectively. A rolling pair type flat rolling mill was realized by interposing a rolling bearing type flat bearing 105 on the bottom and the liner portion (downward from the pass line).
[0004]
Specifically, as shown in FIGS. 7 and 8, in the bottom liner portion, a flat bearing 105 in which a large number of cylindrical rollers 105 a are arranged in a fan shape between a bottom beam 106 and a sled base 107 is an auxiliary member. Assembled via 108. In FIG. 7, reference numeral 109 denotes a thread, and 110 denotes a pressure block.
[0005]
[Problems to be solved by the invention]
However, in the conventional running pair-cross type rolling mill as described above, since the flat bearing 105 is newly provided at the top or bottom of the housing 104, the height of the housing 104 is increased in order to secure the space. This increases the size of the rolling mill and increases the cost.
[0006]
Also, when the existing rolling mill is converted into a running pair-cross type rolling mill, if the above-mentioned rolling bearing type flat bearing 105 is to be used, it will not fit within the window height of the existing housing 104 as it is. , Especially on the bottom side (see the hatched area in FIG. 6).
[0007]
As a result, there is a problem that the strength of the housing 104 is reduced, and a problem that an operation problem (deterioration of productivity, etc.) due to a stoppage of the plant occurs due to a long remodeling work.
[0008]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a running pair cross-type rolling mill that does not require a new space for a running cross plane bearing, and to reduce the running force of the running cross. It is to provide a method.
[0009]
[Means for Solving the Problems]
A rolling mill according to the present invention that achieves the above object is a running pair cross type rolling mill that controls the shape of a plate by crossing upper and lower work rolls and a backup roll during rolling of a plate material. the liner portion interposed between, provided the hydrostatic bearing and the solid contact part of the flat bearing-fly cross, a part of the rolling load acting on the liner portion while borne by the solid contact part, The static pressure bearing portion is characterized in that a static pressure support pocket is formed on a piston having a small diameter and slidable in a large number of cylinders .
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a rolling mill according to the present invention and a method of reducing a running cross operating force thereof will be described in detail with reference to the drawings using examples.
[0015]
[First embodiment]
FIG. 1 is a side view of a running pair-cross type rolling mill showing a first embodiment of the present invention, FIG. 2 is a view taken along the line II-II of FIG. 1, and FIG. 3 is a view taken along a line III-III of FIG. FIG. 4 is a view taken in the direction of the arrow IV in FIG.
[0016]
As shown in FIG. 1, an upper and lower work roll 2 and a backup roll 3 are rotatably supported in a housing 1 of a running pair cross type rolling mill via chocks 4 and 5, respectively.
[0017]
Further, a hydrostatic bearing portion as a running cross plane bearing described later is provided on a sled base 6 constituting a top or bottom liner portion in the housing 1.
[0018]
Specifically, as shown in FIGS. 2 to 4, a small diameter and a large number of static pressure support pockets (surfaces) 8 are formed on the lower surface of the thread base 6 in contact with the bottom beam 7 on the bottom side. A predetermined oil pressure is supplied into the pressure support pocket 8 from an oil pressure source (not shown) via an oil passage 9.
[0019]
For example, 40 static pressure supporting pockets 8 having a depth of 1 mm and a diameter of 120 mm are formed at regular intervals of 10 mm vertically and horizontally with respect to a sled base 6 of 1050 × 660 mm 2.
[0020]
In this embodiment, each of the static pressure supporting pockets (surfaces) 8 bears about 95% of the rolling load acting on the liner portion, and the remaining 5% divides the solid between the lower surface of the thread base 6 and the bottom beam 7. The contact portion M bears the burden.
[0021]
A contact seal 11 for high differential pressure having a pressure resistance of 100 MPa in a standard specification is mounted on an inner peripheral portion of each of the static pressure supporting pockets 8 through an annular groove 10. As a material of the contact seal 11, a high-density polyethylene resin or the like having excellent resistance to protrusion, abrasion resistance and self-lubrication is selected.
[0022]
Although the above is the configuration of the thread base 6 on the bottom side of the housing 1, the thread base 6 on the top side is similarly configured.
[0023]
With such a configuration, the rolling load is now considered at 2100 tonf / housing. Assuming that the load supported by each static pressure support pocket 8 is 1995 tonf (95% load), the remaining 105 tonf (5% load) is the support load at the solid contact portion M.
[0024]
Assuming that the frictional resistance of each of the static pressure supporting pockets 8 can be neglected, a value obtained by multiplying the supporting load at the solid contact portion M of 105 tonf by the friction coefficient is a force required for the running crossing operation. Since the surface where the relative slip occurs is under the oil lubrication condition, when the friction coefficient is considered as 0.1, the crossing operation force during running is 10.5 tonf.
[0025]
This value is equivalent to that of a cylindrical roller type flat bearing (rolling friction coefficient 0.005 × load 2100 tonf = 10.5 tonf).
[0026]
Further, assuming that the required hydraulic pressure p ² is φ110 mm in the range where the hydraulic pressure reaches each static pressure support pocket 8 (the hydraulic working area of the contact seal 11), the area of all 40 is 3.801 × 10 ⁵ mm ^2. = 1995 × 10 ³ ÷ 3.801 × 10 ⁵ = 5.248 kgf / mm ² .
[0027]
On the other hand, when the contact surface pressure pc bears a load in the area surrounded by the broken line in FIG. 2 (excluding the static pressure support pocket 8), the contact area A = (770 × 380) − (π ÷ 4 × 120 ² ×) 18) = 1.215 × 10 ⁵ mm ² , so pc = 105 × 10 ³ ÷ 1.215 × 10 ⁵ = 0.86 kgf / mm ² . With this value, the speed of the running cross is about 1 to 2 mm / sec, so that the seizure problem at the solid contact portion M does not occur.
[0028]
Since the running cross is performed using the flat bearing of the hydrostatic semi-floating system, the running operating force during the running can be small as in the case of the cylindrical roller type flat bearing.
[0029]
In addition, by leaving the load on the solid contact portion M, the amount of oil consumed in each static pressure support pocket 8 can be reduced, and the positioning accuracy can be ensured. In addition, it does not become a disturbance factor in sheet thickness control as in the case of complete floating.
[0030]
In this embodiment, the static pressure semi-floating flat bearing is incorporated in the sled base 6 constituting the liner, so that no additional installation space is required. That is, in the case of a newly-installed rolling mill, it is only necessary to change the design (structure) of the thread base 6 existing before, and it is possible to avoid an increase in the size of the rolling mill housing.
[0031]
On the other hand, when converting an existing rolling mill to a running pair-cross type rolling mill, the above-mentioned structure, that is, the thread base 6 with a built-in flat bearing of a hydrostatic semi-floating type may be replaced, so that it is not necessary to drive the housing. In addition, the strength of the housing can be maintained and the construction period can be shortened.
[0032]
Further, in the present embodiment, since a large number of small-diameter static pressure supporting pockets 8 are provided, it is possible to avoid that the contact seal 11 protrudes from the annular groove 10 and cannot maintain a predetermined static pressure. That is, by using multiple static pressure supporting surfaces, the difference in deformation within the static pressure supporting surface is reduced, and the followability of the seal functions well.
[0033]
Incidentally, since the thread base 6 and the bottom beam 7 as the mating surface thereof are elastically deformed by the rolling load and the static pressure, the clearance between the thread base 6 and the bottom beam 7 becomes large on the large-diameter static pressure supporting surface. In addition, problems such as protrusion of the contact seal 11 are likely to occur.
[0034]
Further, in this embodiment, since the contact seal 11 for high differential pressure is used, it is possible to sufficiently secure the followability to non-uniform deformation (including undulation) in the liner portion, etc. Can be favorably maintained. Incidentally, a backup ring may be provided so that the contact seal 11 has a pressure resistance of 300 MPa.
[0035]
In the above-described embodiment, the static pressure supporting surface of each static pressure supporting pocket 8 is formed in a circular shape. However, the static pressure supporting pocket 8 is formed in a circumferential groove, a spiral groove, a cross-shaped groove, a parallel groove, or the like, and a part of the static pressure supporting surface is formed. May be brought into solid contact to reduce the contact surface pressure.
[0036]
[Second embodiment]
FIG. 5 is a side view showing a main part of a running pair cross type rolling mill according to a second embodiment of the present invention.
[0037]
As shown in FIG. 5, in this embodiment, similarly to the static pressure support pocket 8 of the first embodiment, a small number of stepped cylinders 20 having a small diameter are formed on the lower surface of the sled base 6 in the first embodiment. In addition, a stepped piston (bearing) 21 having a similar shape to the cylinder 20 is slidably accommodated in each of the cylinders 20 via an oil seal 22 in a vertically slidable manner, and a hydraulic chamber 20 a is provided above the piston 21. This is an example in which a static pressure support pocket 21a is formed on the lower surface of the piston 21.
[0038]
A predetermined hydraulic pressure is supplied to the hydraulic chamber 20a from a hydraulic supply source (not shown) via an oil passage 9 formed in the sled base 6, and an oil passage 23 is provided in the static pressure support pocket 21a via an oil passage 23. The hydraulic pressure from the oil passage 9 is supplied via a hydraulic chamber 20a.
[0039]
The dimensional conditions of each member are set such that the force of pushing down the piston 21 from the hydraulic chamber 20a is larger than the oil film pressure reaction force in the static pressure support pocket 21a.
[0040]
In the figure, reference numeral 12 denotes a thread, and reference numeral 13 denotes a pressure block. Although the above is the configuration of the thread base 6 on the bottom side of the housing 1, the thread base 6 on the top side is similarly configured.
[0041]
Also according to this embodiment, a flat bearing of a static pressure semi-floating type by sharing the load between each static pressure support pocket 21a and the solid contact portion M can be realized with the thread base 6 built-in type. The effect is obtained.
[0042]
According to the present embodiment, the piston 21 is pushed out by the force of the hydraulic chamber 20a even if the bottom beam 7 that is the mating surface escapes due to deformation, for example, so that the bearing gap is not greatly opened. An oil leak can be avoided and the static pressure supporting ability can be maintained satisfactorily.
[0043]
It should be noted that the present invention is not limited to the above embodiments, and various changes can be made without departing from the scope of the present invention. For example, the solid contact portion and the hydrostatic bearing portion may be built in another liner portion such as a bottom beam, a structure in which the first and second embodiments are combined, or the hydrostatic bearing portion may be hydraulically operated. Instead of the fluid pressure described above, it may be changed to one utilizing magnetism.
[0044]
【The invention's effect】
As described in detail above, the rolling mill according to claim 1 of the present invention is a running pair cross-type rolling mill that controls the shape of a plate by crossing upper and lower work rolls and a backup roll during rolling of a plate material. Wherein the liner portion interposed between the backup roll and the housing is provided with a hydrostatic bearing portion as a flat bearing for a running gap, so that a running space is not required newly. A flat bearing for crosses can be realized, and if a new rolling mill is used, upsizing can be avoided beforehand.On the other hand, when retrofitting an existing rolling mill to a pair-crossing rolling mill while running, it is not necessary to add housing to the rolling mill. Strength can be maintained and the construction period can be shortened.
[0045]
The rolling mill according to claim 2 of the present invention is characterized in that a solid contact portion is provided together with the hydrostatic bearing portion, and a part of a rolling load acting on the liner portion is borne by the solid contact portion. In addition to the same operation and effect as the first aspect, the consumption of the fluid pressure and the like in the hydrostatic bearing portion can be reduced, and the positioning accuracy can be ensured. In addition, there is an advantage that it does not become a disturbance factor in sheet thickness control unlike complete floating.
[0046]
In the rolling mill according to claim 3 of the present invention, the static pressure bearing portion has a small diameter and a large number of static pressure supporting pockets, and the static pressure supporting pockets are sealed with a contact seal for high differential pressure. Therefore, in addition to the same operations and effects as those of the first aspect, it is possible to sufficiently secure the followability to non-uniform deformation (including undulation) in the liner portion, etc., to avoid oil leaks, and to increase the static pressure supporting ability. There is an advantage that it can be maintained well.
[0047]
The rolling mill according to claim 4 of the present invention is characterized in that the static pressure bearing portion is formed by forming a static pressure support pocket on a piston having a small diameter and slidable in many cylinders. In addition to the functions and effects similar to those described in the item 1, even if the mating surface escapes due to uneven deformation in the liner portion or the like, the piston is pushed out by the force of the hydraulic chamber in the cylinder, so that the bearing gap does not open much and the oil leaks. Therefore, there is an advantage that the static pressure supporting ability can be favorably maintained by avoiding the above problem.
[0048]
A method according to claim 5 of the present invention is directed to a rolling pair cross-type rolling mill for controlling a plate shape by crossing upper and lower work rolls and a backup roll during rolling of a plate material. In the above, the rolling load acting on the liner portion interposed between the backup roll and the housing is shared by the hydrostatic bearing portion and the solid contact portion so as to cross during running. The same operation and effect as the second aspect are obtained.
[Brief description of the drawings]
FIG. 1 is a side view of a running pair cross type rolling mill, showing a first embodiment of the present invention.
FIG. 2 is a view taken in the direction of arrows II-II in FIG.
FIG. 3 is a view taken in the direction of arrows III-III in FIG. 2;
FIG. 4 is a view taken in the direction of the arrow IV in FIG. 3;
FIG. 5 is a side view of a main part of a running pair cross type rolling mill, showing a second embodiment of the present invention.
FIG. 6 is a side view of a running pair cross type rolling mill of a conventional example.
FIG. 7 is an enlarged view of a main part in the same manner.
8 is a view taken in the direction of arrows VIII-VIII in FIG. 7;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Housing 2 Work roll 3 Backup roll 4 Work roll chock 5 Backup roll chock 6 Thread base 7 Bottom beam 8 Static pressure support pocket 9 Oil passage 10 Annular groove 11 Contact seal 12 Thread 13 Pressure block 20 Stepped cylinder 20a Hydraulic chamber 21 Stepped piston 21a Static pressure support pocket 22 Oil seal 23 Oil passage M Solid contact part

Claims (1)

In a running pair-cross type rolling mill in which the upper and lower work rolls and the backup roll are crossed during rolling of a plate material to control the shape of the plate, the liner section interposed between the backup roll and the housing has a running cross. the hydrostatic bearing and the solid contact part of the use planar bearing is provided, a part of the rolling load acting on the liner portion while borne by the solid contact part, the hydrostatic bearing is smaller in diameter and number of cylinders A rolling mill characterized in that a static pressure support pocket is formed in a piston slidable inside .

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